Renal failure resulting from chronic glomerular disease is an important cause of death and disability in the United States and an increasing drain on our national health budget. We propose a multi-centered collaborative controlled study of adult glomerular disease with an aim to: 1. Correlate the clinical manifestations, course, and response to therapy of patients with glomerular disease to the specific pathologic changes observed in kidney tissue. To ascertain whether measureable statistically significant benefits in mortality and morbidity are conferred within the period of observation by currently proposed therapeutic agents. 3. Continue our organization, cooperating investigators and hospitals in a frame-work for the controlled study of renal disease that may ultimately be extended to other investigations. The studies proposed under this application include a) a study of the adult idiopathic nephrotic syndrome and its response to alternate-day prednisone therapy, b) a study of membranous nephropathy including a randomized prospective trial of cyclophosphamide therapy of patients with moderate renal failure, c) a randomized prospective study of the effect of plasmapheresis in the treatment of rapidly progressive glomerulonephritis, d) a study of glomerular diesease with non-nephrotic proteinuria.